Strange (new) transcoding behavior with Plex on Synology DS218+ for some remote users

Both of my users now have player version 5.25.3, but only one of them can view transcoded media. I’m now fairly certain this is a Samsung thing and not a Syno thing, but does anybody have any ideas?

Edit: Should have just gone over to the smart TV section and found what I was looking for: https://forums.plex.tv/t/playback-error-on-samsung-tv I think this can close out as it’s not a Synology problem.